1. Field
The disclosure relates to techniques for noise shaping the power density spectrum of an output voltage generated by switching circuitry.
2. Background
Switched-mode power supplies (SMPS's) are commonly employed for their efficient power-delivery capabilities. In an SMPS, high- and low-side switches may be operated to regulate an output voltage, with the switches ideally dissipating no DC power. In some cases, however, the switching action undesirably generates noise at certain frequencies, which may interfere with other portions of circuitry provided with the SMPS. For example, in a wireless transceiver, the SMPS may be provided as part of an envelope-tracking (ET) system for a transmitter power amplifier. In this case, the operation of the high- and low-side switches may undesirably cause interference with an integrated receiver at one or more receive (RX) frequencies.
It would be desirable to provide simple and targeted techniques for reducing the noise generated by switching circuitry at one or more frequencies.